Right Subassembly??

[Casper46]

Hi

I have a problem with maintaining a dtch depth in fill conditions please see pic below.

Anyone know how I can set a condition that will make the foreslope extend to maintain the dtich depth based on the daylighting point of the outgoing ditch slope?

Many thanks

Chris

[doni49]

What portions vary?  Will Distance X (per the following) be a set distance?  Or will that vary?

Does it go from the EOP down the slope (at a specific slope) to the daylight?  Then what distance?  What slope for line X?

EDIT:  Better question:  What are all your "known values" (will not vary) and what are your "unknown values" (will vary)?

[Casper46]

Thanks for the response.

The only things that can change are the Daylight line from the EOP targetting the surface and the daylight line targeting the existing surface circled

"x" is a set distance of 0.5m, I need to maintain the depth of the swale based on the circled point, and not have a raised bund etc

Thanks

[doni49]

What are you going to use to determine the horizontal location of that circled point?  If you know the horizontal location of that point, you could use "LinkOffsetonSurface" and work your way back toward the road.

EDIT:  Based on your reply, it sounds like the daylight slope and offset distance will vary.  If that's what you want and you know the horizontal location of the circled point, it sounds feasible.

[Casper46]

Hi



The horizontal offset is based on a set swale profile, the subassembly's
shown are linkslopetosurface (in fill condition) and daylightbasin.



I want the circled point to be the interface between the ditch and the
target surface, it's fine in cut and in fill areas on flat ground but
not

in scenarios like I've shown.



Cheers

[doni49]

Something is going to have to give way. 

If you want the circled point to be at a specific offset, then LinkOffsetonSurface can be used to find where the horizontal offset hits the surface.  Then use your slopes to construct the ditch.  Then from there, you have your 0.5m distance (DistanceX). 

[Casper46]

Yeah that's the trouble, because the horzontal offset will vary based on the topography, I think a custom subassembly may be the only answer

[doni49]

I think you're going to run in to the same problem with a custom SA.  The horizontal offset CAN vary -- as long as you can tell the SA WHERE it is.  Can you define it with an alignment or a feature line?

[Casper46]

Unfortunately not as the ground is not consistant so the offset would very, think this should be much simpler to sort out

[sboon]

Trying to sort out the logic of how this would work.  Does this make sense?

The daylight point marked with the yellow circle needs to be on the existing surface, but also has to follow a specified slope for the ditch to drain.  A horizontal alignment could be used here with a surface profile.  Draw a construction line on the profile view at the specified slope and then start tweaking the alignment PIs, until the surface profile matches the line, within tolerance.

From the shoulder of the road add a MarkedPoint and LinkOffsetOnSurface, targeted to the new alignment.  Use a ditch subassembly or a series of generic links to build the ditch and the 0.5m horizontal piece.  Finish it off with LinkToMarkedPoint back to the shoulder.

Steve
Please use the Accept as Solution or Kudo buttons when appropriate